Method and apparatus for treating body tissues and bodily fluid vessels

ABSTRACT

Methods for treating bodily tissues and fluid vessels are disclosed. According to a method of repairing a perforation in a bodily fluid vessel, a viscous, moldable substance is inserted into the vessel at the location of the perforation. A path is opened through the moldable substance to permit fluid flow through the vessel. According to a method of introducing a tissue-killing substance into a bodily fluid vessel, a catheter is provided that has a blocking mechanism configured to selectively block and unblock the vessel. The catheter also has a delivery system that is configured to introduce the tissue-killing substance into the vessel. The vessel is substantially blocked upstream of a selected tissue using the blocking mechanism. The tissue-killing substance is introduced into the vessel through the delivery system, and the vessel is unblocked when the tissue-killing substance has substantially traveled toward the selected tissue. According to a method of occluding a bodily fluid vessel, a catheter is provided that has a first passage. The first passage has an occlusion element housed therein. The catheter is positioned in the vessel, and the occlusion element is moved out of the passage and into the vessel to thereby occlude the vessel. A catheter is also disclosed that may be used with the above methods.

FIELD OF THE INVENTION

The invention is directed to methods of using a balloon catheter totreat perforated bodily fluid vessels, diseased tissues, and otherirregularities in bodily fluid vessels such as arteriovenous fistulaeand aneurysms.

BACKGROUND OF THE INVENTION

Treatment of heart disease has traditionally been a highly traumaticendeavor. For many years surgeons would be required to conduct majorsurgery to correct even relatively minor conditions. Such "open-heart"operations are highly traumatic for the patient and may therefore not bean option for those whose bodies cannot withstand such trauma.Open-heart operations are also expensive and may be risky. There is alsoa possibility of the patient contracting an infection during his or herextended stay in a medical care facility. For these reasons, someconditions may not merit treatment if open-heart surgery is required fortheir treatment.

The use of low-trauma surgery devices and techniques has increased thetreatment and success rates for many conditions that are either toorisky or too expensive to perform during open-heart surgery. Thecatheter is one such low-trauma device that has been especiallysuccessful in the treatment of cardiovascular and other conditions. Atypical catheter is a flexible, hollow small-diameter tube that isthreaded through a body system (such as the cardiovascular system) untilit reaches a location that requires treatment. An advantage of acatheter is that only a small incision need be made to insert thecatheter into the body. This significantly reduces the traumaexperienced by the patient and dramatically reduces recovery time.Furthermore, depending on the procedure, only local anesthesia may beneeded. This reduces the risk and cost of the procedure. Catheters havebeen successfully used in angioplasty procedures and in the delivery ofstents and other medical devices into selected areas of the body.

One procedure that has met with limited success using low-traumasurgical techniques is the killing off or elimination of tissues such asthe septum of the heart. If a tissue-killing substance such as alcoholis inserted into an artery leading to the septum, there is a risk thatsome of the alcohol may travel instead through arteries leading to otherportions of the heart. This would damage other portions of the heart,and a heart attack may result. Known infusion techniques have not beenable to reliably deliver alcohol to a desired tissue while preventingthe alcohol from damaging other tissue.

Another procedure that has met with limited success is the repair ofperforations or ruptures in blood vessels. Such perforations may provefatal if the rate of the resulting internal bleeding is substantial.Surgery is often required to repair the perforation, but in high-riskcircumstances surgery may not be advisable.

Still another procedure that has, until the present invention, createdchallenges for the surgeon is the occlusion of small, inconsequentialvessels. When a smaller vessel is perforated, the physician may decideto permanently block, or occlude, the vessel. Known catheter techniquesare unreliable because they do not have a means to hold the catheter inplace while treating the damaged vessel. Furthermore, known techniquesmay not work with vessels having smaller diameters.

SUMMARY OF THE INVENTION

The invention provides a method of repairing a perforation in a bodilyfluid vessel. According to the method, a viscous, moldable substance isinserted into the vessel at the location of the perforation. A path isopened through the moldable substance to permit fluid flow through thevessel.

Another aspect of the invention provides a method of introducing atissue-killing substance into a bodily fluid vessel. According to themethod, a catheter is provided that has a blocking mechanism configuredto selectively block and unblock the vessel. The catheter also has adelivery system that is configured to introduce the tissue-killingsubstance into the vessel. The vessel is substantially blocked upstreamof a selected tissue using the blocking mechanism. The tissue-killingsubstance is introduced into the vessel through the delivery system, andthe vessel is unblocked when the tissue-killing substance hassubstantially traveled toward the selected tissue.

Still another aspect of the invention provides a catheter for use inoccluding a bodily fluid vessel. The catheter includes a length offlexible tubing that has an opening at a distal end of the tubing. Afirst passage, provided within the tubing, is in communication with theopening. An occlusion element is housed inside the passage and isconfigured to exit the passage through the opening to at least partiallyocclude the vessel.

Yet another aspect of the invention is a method of occluding a bodilyfluid vessel. According to the method, a catheter is provided that has afirst passage. The first passage has an occlusion element housedtherein. The catheter is positioned in the vessel, and the occlusionelement is moved out of the passage and into the vessel to therebyocclude the vessel.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a side elevational, partial cutaway view of a first catheteraccording to an embodiment of the invention.

FIG. 2 is a side elevational view of a body fluid vessel during aperforation repair process according to the invention.

FIG. 3 is a side elevational view of another portion of the perforationrepair process.

FIG. 4 is a side elevational view of another portion of the perforationrepair process.

FIG. 5 is a side elevational view of another portion of the perforationrepair process.

FIG. 6 is a side elevational view of another portion of the perforationrepair process, showing how a second catheter is used therewith.

FIG. 7 is a side elevational view of another portion of the perforationrepair process.

FIG. 8 is a side elevational view of another portion of the perforationrepair process.

FIG. 9 is a side elevational view of a portion of an alcohol infusionprocess.

FIG. 10 is a partial cutaway view of the first catheter shown in FIG. 1prepared for use in a vessel occlusion process.

FIG. 11 is a side elevational view of a portion of a vessel occlusionprocess.

FIG. 12 is a side elevational view of another portion of the vesselocclusion process.

FIG. 13 is a side elevational view of another portion of the vesselocclusion process.

FIG. 14 is sectional view taken along line 14--14 in FIG. 13.

DETAILED DESCRIPTION OF THE DRAWINGS AND BEST MODE FOR CARRYING OUT THEINVENTION

FIG. 1 depicts a first catheter 10 that may be used with the processesand procedures disclosed herein. First catheter 10 includes a flexible,generally cylindrical length of hollow tubing 12. The tubing preferablyhas an outside diameter of about 1-4 mm. A distal end 14 of the firstcatheter has an opening or aperture 16. A first passage, shown as afirst lumen 18, runs the length of catheter 10 and communicates withaperture 16. First lumen 18 preferably has an inner diameter of about0.018-0.038 inches. The first lumen permits fluids or colloids to beselectively introduced into a vessel, as will be described below. Afirst flexible membrane, shown as a first balloon 20, is secured totubing 12 adjacent distal end 14. First balloon 20 has an interior 22that varies in volume when expanded and contracted. A second passage,shown as a second lumen 24, runs the length of first catheter 10 andcommunicates with interior 22 of the first balloon through intermediateapertures 26 that pass through tubing 12. A controlling fluid (notshown) flows within second lumen 24 and is controlled by an operator toexpand/inflate and contract/deflate the first balloon. The first balloonfunctions as a flow-blocking mechanism to block the flow of blood orother fluid through a vessel while a surgical technique or process isbeing completed. As such, first balloon 20 is very compliant andinflates with a very slight change in pressure within second lumen 24.First balloon 20 preferably has an outer diameter of about 2-8 mm whenfully inflated.

FIGS. 2 through 8 show how first catheter 10 may be used to repair aperforation P in the wall W of a bodily fluid vessel V, which may be anartery or a vein. A guide wire 30 is first inserted into vessel V usingknown methods. First catheter 10, with first balloon 20 deflated, isthreaded along guide wire 28 until distal end 14 of the catheterapproaches perforation P (FIG. 2). The operator inflates first balloon20 (FIG. 3) by controlling the flow of controlling fluid (not shown)within second lumen 24 and interior 22 of the first balloon. In itsinflated state, first balloon 20 blocks the normal flow of blood Bthrough vessel. A viscous, moldable substance such as colloid C, whichhas been inserted into first lumen 18, is then released into the area ofthe vessel surrounding perforation P (FIG. 4). The viscous, moldablesubstance may include any biocompatible substance that is fluid enoughto be directed through a catheter and that is in a moldable stateimmediately after being inserted into the vessel. The viscous, moldablesubstance must also have a viscosity or consistency such that it doesnot freely flow through perforation P or along vessel V. The viscous,moldable substance may be designed to coagulate, cure, set or hardenover time. Examples of suitable substances include thrombin, gel, gelfoam, the thrombin collagen developed by Vascular Solutions, or otherbiocompatible substances. Blood removed from the patient and allowed tothicken, perhaps with the aid of protamine, may also be a suitablemoldable substance.

After colloid C has been released into vessel V, first balloon 20 isdeflated by reducing the pressure and/or flow of controlling fluid (notshown) within second lumen 24 (FIG. 5). The operator withdraws firstcatheter 10 from vessel V.

A second catheter 30 is then threaded along guide wire 28 into vessel V(FIG. 6). Second catheter 30 includes a second flexible membrane, shownas a second balloon 32, that is controllable in a manner similar tofirst balloon 20. Specifically, second catheter 30 has an inner passageor lumen (not shown) that communicates with the interior 34 of secondballoon 32. The second balloon has a length l that is longer than thedeposit of colloid C in the vessel. The operator moves the distal end 36of the second catheter through colloid C so that second balloon 32extends from either end of the colloid deposit, as shown in FIG. 6.Second balloon 32 is then inflated (FIG. 7), and colloid C is pressedagainst wall W of the vessel. Since colloid C is thick or viscuous, thecolloid will not be pressed through perforation P. Instead, theexpanding second balloon creates a path T through the colloid such thatblood B may flow unimpeded therethrough upon deflation and withdrawal ofsecond balloon 32, second catheter 30 and guide wire 28 (FIG. 8).Because the colloid isolates perforation P from path T, the perforationis effectively repaired.

The above process is useful for repairing perforations in blood vessels,but may also be used in repairing perforations or ruptures in otherfluid-carrying vessels in the body. The above process may, for example,also be used to repair arteriovenous fistulae or aneurysms.

First catheter may also be used to kill or eliminate a desired tissue.For instance, in a case of idiopathic hypertrophic subaortic stenosis orif the septum of the heart is diseased, it may be necessary or desirableto kill the tissues comprising the septum of the heart. This may beaccomplished by inserting a tissue-killing substance, such as alcohol,into the septum. First catheter 10 provides a way for such an alcoholinfusion process to be performed without endangering the life of thepatient.

To perform this procedure, guide wire 28 is placed into the leftanterior descending (LAD) coronary artery of the heart and into a septalbranch S of the LAD artery (FIG. 9). First catheter 10 is guided alongguide wire 28 until first balloon 20, in a contracted state, has enteredseptal branch S. The operator inflates first balloon 20 as previouslydescribed. An amount of alcohol A is released or delivered through firstlumen 18 into septal branch S and is permitted to flow toward the septum(not shown), where the alcohol kills the tissue of the septum. Firstballoon 20 serves as a blocking mechanism to prevent the flow of alcoholA out of the septal branch and into the LAD artery, where the alcoholwould otherwise flow and destroy other tissues in the heart. By pressingagainst the interior wall W of septal branch S, first balloon 20 holdsfirst catheter 10 in place while the alcohol is infused into the septalbranch. The operator completes the alcohol infusion process by deflatingfirst balloon 20 and removing first catheter 10 and guide wire 28 fromseptal branch S and LAD artery.

It may sometimes be necessary to provide an electrical impulse to theheart after the alcohol infusion process is complete. This "pacing" ofthe heart may be accomplished by transmitting the electrical impulsethrough guide wire 28 prior to removing the guide wire from the septalbranch or the LAD artery.

First catheter 10 may also be used to permanently occlude a bodily fluidvessel. For instance, it may be determined that a perforated orotherwise damaged blood vessel will be difficult or risky to repair andthat occlusion of the vessel is the most feasible way to stop theinternal bleeding through the perforation. Alternately, it may bedesirable to occlude a vessel that is the source of the filling of ananeurysm, or if the vessel in fact forms into an aneurysm or anarteriovenous fistula. Such vessels may include arteries related to theheart, brain, intestines or the lower limbs. FIG. 10 shows firstcatheter 10 that has been modified to be used in such a vessel occlusionprocess. First and second wire segments 40, 50 are inserted into firstlumen 18. First wire segment 40, which may be considered an occlusionelement or a coil, is substantially shorter than second wire segment 50.A first end 42 of coil 40 is disposed at distal end 14 of first catheter10. Coil 40 is made of a flexible, resilient biocompatible material. Thecoil is formed to have a substantially planar spiral shape (FIGS. 13 and14) with a maximum diameter d similar to the inner diameter of thevessel that is to be occluded. However, coil 40 is capable of beingresiliently deformed so that it may be placed into first lumen 18. Coil40 is depicted as having a spiral, substantially planar shape whendelivered into the vessel, but coil may alternatively be shaped in otherforms as required. For example, the coil may have a non-planar spiralshape, such as conical, frusto-conical or helical. The coil may alsohave a serpentine or an irregular shape.

A first end 52 of second wire segment 50 is positioned to be in contactwith a second end 44 of coil 40 while the coil is inside first lumen 18.Second wire segment 50 passes substantially through the entire length offirst lumen 18, and a second end (not shown) of the second wire segmentis configured to be articulated or manipulated by an operator to axiallymove the second wire segment along the passage. Second wire segment 50is constructed of a flexible, bendable biocompatible material and iscapable of transmitting an axial force along its length.

FIGS. 11-13 show a method of using first catheter 10 to occlude a bloodvessel V. The operator inserts first catheter 10 into vessel V. Firstballoon 20 is expanded or inflated (FIG. 11) to block blood flow intovessel V and to hold first catheter 10 in place during the occlusionprocess. The operator manipulates the second end (not shown) of secondwire segment 50 to axially move the second wire segment toward distalend 14 of the first catheter. First end 52 of second wire segment 50contacts second end 44 of coil 40 and urges the coil out of aperture 16(FIG. 12) and into vessel V. Once free of the first catheter, the coilresiliently reverts to its original planar spiral shape and contacts thewall of the vessel (FIG. 13). The coil substantially blocks normal bloodflow in the vessel and aids in the normal blood clotting process. Theoperator completes the occlusion process by contracting or deflatingfirst balloon 20 and removing first catheter 10 from the vessel.

It may be necessary or advisable to insert multiple coils into a vesselduring an occlusion process. In such a case, multiple coils may bedelivered into the vessel by repeating the above process as many timesas desired. Alternatively, multiple coils may be serially inserted intothe first lumen of the first catheter and inserted into the vessel asdesired by manipulating the second wire segment.

The above vessel occlusion method may be used to occlude a damagedvessel, and may also be used if there is an ischemic condition, i.e., alack of blood flow in a vessel due to a steal phenomenon, which is adiversion of blood from its normal course. The method may also be usedin the neurovascular anatomy when either a tear or perforation ispresent in a vessel or an aneurism is present. Alternatively, theperforation repair method previously described may also be used toremedy these conditions.

An advantage of using first catheter 10 in the above methods is that thevery compliant nature of first balloon 20 prevents injury or trauma tothe vessel that is blocked. Another advantage is that first balloon 20holds the catheter in place and prevents the catheter from beinginadvertently moved during a process. Another advantage is that firstpassage 18 is large enough to deliver semi-liquid substances, such as acolloid, to a desired region in a vessel. First passage is also largeenough to deliver solid occlusive elements such as coilable wire to adesired vessel. Another advantage is that first catheter 10 may be usedwith or without a guide wire as described above. In the case of thevessel occlusion process, second wire element 50 provides the neededstiffness instead of a guide wire. Yet another advantage is thataperture 16 is located immediately adjacent first balloon 20. Thisenables an accurate delivery of alcohol or colloid relative to the firstballoon. Still another advantage is that first catheter 10 may be usedfor many different surgical procedures. A manufacturer saves costsbecause it does not need to make a separate catheter product for each ofthe different procedures. Surgeons also save training time because theydo not need to learn how to a different catheter for every desiredprocedure. Finally, first catheter provides a way to safely andaccurately accomplish procedures that previously have been accomplishedonly with great difficulty and risk to the patient.

While the invention has been disclosed in its preferred form, thespecific embodiments thereof as disclosed and illustrated herein are notto be considered in a limiting sense as numerous variations arepossible. Applicant regards the subject matter of the invention toinclude all novel and non-obvious combinations and subcombinations ofthe various elements, features, functions and/or properties disclosedherein. No single feature, function, element or property of thedisclosed embodiments is essential. The following claims define certaincombinations and subcombinations which are regarded as novel andnon-obvious. Other combinations and subcombinations of features,functions, elements and/or properties may be claimed through amendmentof the present claims or presentation of new claims in this or a relatedapplication. Such claims are also regarded as included within thesubject matter of applicant's invention irrespective of whether they arebroader, narrower, or equal in scope to the original claims.

I claim:
 1. A method of repairing a perforation in a bodily fluidvessel, comprising:providing a first catheter, and inserting the firstcatheter into the vessel, stopping fluid flow in the vessel, afterstopping fluid flow, inserting through the first catheter a viscous,moldable substance into the vessel at the location of the perforation;providing a second cather having a second flexible membrane attachedthereto; and opening a path through the viscous, moldable substance byinserting the second cather into the moldable substance and expandingthe second flexible membrane to permit fluid flow through the vessel. 2.The method of claim 1, further including providing a guide wire throughthe vessel, and wherein the insertion of the first catheter isaccomplished by moving the first catheter along the guide wire.
 3. Themethod of claim 1, further including providing a first catheter with afirst flexible membrane attached thereto, wherein expansion of the firstflexible membrane stops fluid flow in the vessel.
 4. The method of claim1, wherein the viscous, moldable substance hardens over time, andwherein the path is opened through the moldable substance after themoldable substance has at least partially hardened.
 5. The method ofclaim 4, wherein the positioning of the second catheter is accomplishedby moving the second catheter along a guide wire that is placed in thebodily fluid vessel.
 6. The method of claim 1, wherein the firstcatheter is removed from the vessel prior to moving the second catheterinto the vessel.
 7. A method of repairing a perforation in a wall of abodily fluid vessel, comprising:providing a first catheter, the firstcatheter having a distal end and a first flexible membrane disposedadjacent the distal end, the first catheter further including first andsecond passages, wherein the first passage communicates with an aperturein the distal end and the second passage communicates with an innervolume defined by the flexible membrane; positioning the first catheterinto the vessel adjacent the perforation; inflating the first flexiblemembrane so that fluid flow through the vessel adjacent the perforationis substantially blocked; releasing a viscous, moldable substancethrough the second passage and the aperture so that the moldablesubstance substantially fills a region of the vessel at the perforationwithout passing through the perforation; deflating the first flexiblemembrane; removing the first catheter from the vessel; providing asecond catheter, the second catheter having a distal end and a secondflexible membrane adjacent the distal end of the second catheter, thesecond catheter further including first and second passages; introducingthe second catheter into the vessel; positioning the catheter so thatthe distal end of the second catheter passes through the moldablesubstance; expanding the second flexible membrane to press the moldablesubstance against the wall of the vessel; deflating the second flexiblemembrane; and removing the second catheter from the vessel.